1. Technical Field
The present invention relates to an electrophoretic display device and an electronic device.
2. Related Art
Display devices such as liquid crystal devices have come to be widely employed in mobile phones, TV sets, watches, and so forth, and are advancing in terms of functions and performances. In particular, rapid developments are being made for achieving reductions in frame width, thickness, and weight, in response to demands for better design and functions from users. The demand for thinner devices is urging development of paper-like display devices that can be bent or folded, such as flexible display devices, as an advanced form of flat display devices. An example of such flexible display devices, which can be made thinner and lighter because they have a similar nature to paper, is an electrophoretic display (EPD) device.
An EPD device includes a microcapsule layer serving as a display layer interposed between a driving substrate on a lower side and a transparent electrode film on an upper side, and hence reliability in terms of mechanical and electrical connection of electrical connection points between the driving substrate and the transparent electrode film is a key issue. Accordingly, for example as disclosed in JP-A-2009-222902, a conductive material is provided for electrical connection between the driving substrate and the transparent electrode film, with the capsule layer interposed therebetween.
The foregoing connection arrangement between the upper and lower substrates has, however, a drawback in that the conductive material of the electrical connection point may become separated from the upper or lower electrode in the case where the conductive material is thinner than the display layer between the upper and lower electrodes, resulting in significant degradation of reliability in terms of mechanical and electrical connection.
On the other hand, in the case where the conductive material is thicker than the display layer between the upper and lower electrodes and, for example, where the conductive material is located close to the display layer, the display layer may become separated from the upper or lower electrode layer because of the difference in thickness between the conductive material and the display layer, which leads to defective display performance. This could be avoided by providing the conductive material at a position sufficiently distant from the display region thereby mitigating steep inclination of the transparent electrode film arising from the difference in thickness between the conductive material and the display layer, however such an arrangement is not realistic because a large space would be required around the display region.